Association study of optineurin gene polymorphisms T34T and M98K with normal tension glaucoma in a Turkish cohort

To investigate the relationship between normal tension glaucoma and Optineurin (OPTN) gene polymorphisms in the Turkish population. Two single nucleotide polymorphisms in the OPTN gene, T34T and M98K, were genotyped from 72 normal tension glaucoma patients and 100 control subjects and compared between the groups. The T34T polymorphism genotype frequencies were determined as 31/33/8 (wild type/heterozygous/mutant) and 42/46/12 in the normal tension glaucoma and control groups, respectively. The G/A allele frequencies were 95/49 in the normal tension glaucoma group and 130/70 in the control group. The M98K polymorphism genotype frequencies were 66/5/1 and 89/10/1, and the T/A allele frequencies were 137/7 and 188/12 in the normal tension glaucoma and control groups, respectively. The genotype and allele frequencies of the T34T and M98K polymorphisms were similar between the normal tension glaucoma and control groups (p > 0.05). These findings indicate that the T34T and M98K polymorphisms were not associated with the disease in this cohort. However, given the low frequency of the mutant genotypes and the modest sample size, these results do not definitively rule out a predisposition. Further large-scale studies with a broader molecular analysis spectrum will be beneficial to fully elucidate the underlying genetic etiology of normal tension glaucoma.